Electric furnace and process of heating substances.



E. F. VON WILMOWSKY, DBOD.

E. J. PRINDLE, EXEGUTOR ELECTRIC FURNACE AND PROCESS OF HEATING SUBSTANCES.

APPLICATION FILED 001228, 1896. 1,094,354, 7 Patented Apr. 21, 1914.

f W fh-/Z I w UNITED strarug rA'rEN T OFFICE.

ERWIN F. VON WILMOWSKY, OF BOSTON, MASSACHUSETTS; EDWIN J. PRINDLE, EXECU- TOR ,OF SAID VON WILMOWSKY, DECEASED, ASSIGNOR TO MRS. OLGA PIEPEB, OF

ro'rsnam, GERMANY ELECTRIC FURNACE AND PROCESS HEATING SUBSTANCES.

Patented Apr. 21, 1914.

Application filed October 28, 1896. Serial No. 610,285.

To all whom it may concern:

Be it known that I, ERWIN F. von WIL- MOWSKY, a citizen of the United States of America, residing at the city of Boston, Commonwealth of Massachusetts, have invented certain new and useful Improvements in Electric Furnaces and Processes of Heating Substances 'Uniformly and at a Controllable Temperature in Electric Arcs, and that the following is a description of the invention which will enable those skilled in the art to which it appertains to make and use the same, reference being had to the different figures of the accompanying drawings, in which the same letters designate identical or analogous parts.

My invention relates to electric furnaces and processes of heating substances, in which the electric arc is formed and utilized for the purpose of heating, and the principal object of the invention is to regulate the position of the are at will and control its movements to insure equal and thorough heating and equal wear of the furnace parts. Heretofore apparatus of this class has been so constructed that the electrical discharge or archas been located, and hence an intense effect has resulted adjacent thereto with but little heat at other portions of the furnace. Vith suchapparatus rapid destruction of the heating chamber ensues, and

it is difficult to act on a charge, of material in a-uniform manner. In carrying my invention into effect I provide a heating chamber in which an arc is established and maintained between adjacent electrodes, the said electrodes being parallel to each other, and the arc is caused to change its position along the length of said electrode in order to heat the entire heatin v chamber. In t e embodiment of my invention illustrated, and which I shall describe, one of the electrodes is a hollow cylinder, of carbon, which constitutes the heating chamber of the furnace. The other electrode is a carbon rod extending through said cylinder. The arcing surfaces of these electrodes may be concentric cylindrical surfaces, and when a rotatingare or arc-disk is established between such surfaces, it is desirable to be able the purpose of insuring equal wear and for producing heat throughout the length of the heating chamber. This I accomplish by an arrangement producing what may be called a travelin are. Besides, it is desirable to make t e heat uniform atany given time in as long a part of the heating chamber as possible; this I accomplish by what may be called an oscillating arc, which is an arc made to move automatically to and fro in quick succession.

The invention is illustrated in the accompanying drawings, in which t Figure 1 is a longitudinal section of the essential elements of the furnace and its circuit connections, the details of construction not being shown ;Fig. 2 is a diagram of the furnace with a modified form of rheostat whereby the movements of the are are caused to be automatic and periodic.

Referring to the drawings, A represents a hollow cylindrical electrode open at its ends to receive and discharge the substance to be treated, and made of carbon. This electrode thus constitutes the heating chamber of the furnace, and is rotatably mounted in an inclined position so that the charge admitted at the upper end from hopper a will be equally heated and will steadily travel downward toward the lower end to dischargespouta The mounting of electrode A may be effected in any suitable manner, such as that shown in Fig. 1, where it will be seen that end collars are provided of which a? has a gear engaged by pinion a for. rotating the cylinder, and collar a engages supporting rollers a and a, all mounted on any suitable supports. Any gases may escape at hopper a after giving up heat .to the fresh incoming charge. The other electrode is shown as a carbon rod B extending longitudinally within electrode A, and having its ends supported in any desired manner. This rod B may have a cylindrical surface, and be centrally located within electrode A, so that the two electrodes will present substantially parallel concentric cylindrical arcing surfaces. Electrode A is surrounded by a solenoid a which, when energized, causes the rapid rotation of the are around the central electrode, producing what may be termed an 6 value produce the same amount of amperes,

arc-disk. The solenoid is connected with the same source of .current as that supplying the electrodes,

In order to change the position of the arc and cause the arc to move from end to end of the heating chamber, I connect one pole of the source of current, which may be an alternating current generator G, to both ends of one electrode by branch circuits in which are interposed variable resistances. The otherpole of the source of current is similarly connected to the other electrode. Such an arrangement, as shown in Fig. I,- comprises a rheostat R connected at D and E with the ends of electrode Band having its movable contact 1" connected to one pole of the generator. A second'rheostat T is connected at F and f with the ends of electrode A by brushes 2." and 25 The movable contact t of this rheostat is connected to the other pole of the generator. The positions of the movable contacts 1- and t can be changed at will, but they are usually moved both at the same time in the same irection and proportionately, the position of the arcdisk being thereby regulated-so that the lat ter may be made to travel through the whole tube, to and fro. When the variable point is set so that the current enters mainly on the right-hand side, the arc-disk will move to the left, and vice versa.

In the operation of the furnace, the charge being fed at hopper a, the arc is established between the electrodes and is spread into an arc-disk b the action of solenoid a The position 0 this arc, or are disk, within the cylinder depends upon the position of movable contacts r and t, and hence the relative resistance of the shunt circuits conducting current to the ends of the electrodes. The movements of the arc are due to the tendency of an are established between parallel electrodes to move away from the end where the current is supplied. When the current is supplied to both ends of the electrodes, the motion of the arc is determined by the variation betwen the two currents concerned. As the resistances in the branch circuits may be varied, and the currents in said circuits thereby varied, the arc may be shifted. The relation of the resistances is proper when i for instance, the added resistance in the cirof current supply for the left-hand termi-' cuits connected to the left-hand terminals of the two electrodes, plus the electric resistance of the left-hand parts of the electrodes (reaching from said left-hand terminals to the place where the arc stays, under the given adjustment) is equal to the sum of the. two corresponding resistances on the right-hand. It is supposed that the source nals and for the right-hand terminals has the same voltage. The samevolts applied to resistanceswhich have the same aggregate that is the left-hand current and the righthand current (which jointly form the are) are in this case equal. It has been said above the motion of the arc is determined by the variation between the two currents concerned. Now, in the case just supposed there is no such variation, and it therefore follows that there is no motion of the are, that is, the arc remains at a certain place between the electrodes for a given adjustment of the resistances. This is the meaning of the above-mentioned proper relation.

In order to compel the arc to travel rapidly and automatically from end to end of the heating chamber, I provide the arrangement shown in Fig. 2, by which the changes in resistance are rendered periodic and automatic. In that figure, H is a rotating rheostat having a commutator 72, connected to one pole of the generator by a contact brush 7, while the ends of the rheostat are connected to the ends of electrode B through contact rings D and E and the brushes engaging the same. Similarly, the rotating rheostat I having commutator z engaged by brush 6'', the latter connected to the other pole of the generator, and contact rings F and f, is similarly connected to electrode A. The rheostats are preferably geared together as shown to secure synchronism. The direct analogy between this arrangement and that shown in Fig. 1 is at once apparent. In the latter case adjustable contacts of the rheostats remain stationary and it is the resistance segments which move.

The resistance of the rheostat may be ten times that of the carbon rod. I may employ alternating currents with the apparatus shown in Fig. 2. The speed of rotation of the rheostats is preferably about twenty revolutions per minute for comparatively low temperatures, and the higher the temperature the hi her the speed, within wide limits.

The sub ect matter of this application for patent is an improvement upon that of my companion application Serial No. 610,286 filed simultaneously herewith, and the generic features common to both applications but are claimed in the said companion application.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a device for controlling an electric discharge, the combination of electrodes parallel and opposite to each other, providing between them an air-gap :of considerable width, a divided circuit for each ofsaid electrodes, and means to supply the branches of said divided circuit with pulsating currents of substantially one and the same periodicity.

2. In a device for controlling an electric discharge, the combination of arallel electrodes, a divided circuit for sald electrodes,

are not claimed in the present application, I

' and sources of pulsating currents supplied circuit.

7 ends.

i trodes,

, formed between 4. In an electric furnace, parallel eleca heating chamber surrounded by solenoid-turns and sources of two pulsating curtents and electric conductors joining the four ends of saidparallel electrodes with said sources and completing a divided cir- 5. In an electric" furnace, parallel electrodes of which the "one issurrounded by the other one and solenoid turns surrounding the same, mechanical support of each electrode at both ends, in combination with a divided 'ii'cuit and a source for supplying differing currents to the electrodes at both 6. In an electric furnace, a pair of concentric cylindrical electrodes and means to rotate the same, in combination with solenoid turns and a divided circuit supplying each end of said pair of electrodes with a pulsating current.

' 7. In an electric furnace, the combination of two long electrodes parallel and opposite to each other, whereby an air-gap of considerable width. is formed between them, mechanical support at both ends of said electrodes, electrical .means to cause an are said electrodes to travel along said electrodes, means to cause the arc to move in a direction substantially parallel to the axes of said electrodes.

8. In an electric furnace, the combination of electrodes parallel and opposite to each other, whereby a long air-gap of substantially uniform, width is provided between said electrodes, a source of supply of electric current, connections between said source and each end of each of said electrodes, and means for simultaneously varying the amount of current su plied to adjacent ends of said electrodes, w ereby an are formed between said electrodes may be caused to reciprocate along said electrodes.

9. In an electric furnace, the combination I of a hollow electrode, an electrode within said first-mentioned electrode, means for supplying electrical energy to said electrodes, and means for alternately varying the energy supplied to adjacent ends of said electrodes.

10. In ah electric furnace, the combination of ahollow electrode, an electrode within said first-mentioned electrode, means for and other electrical electrical energy to said elecsupplying for alternately varying the trodes, means energy supplied to adjacentends of said electrodes, and means for causing the arc to rotate about the inner electrode.

11. In an electric furnace, the combination of a furnace chamber having a hollow cylindrical electrode, an electrode within and concentric to said first-mentioned electrode, a source of electricity, connections to both ends of each of said electrodes, means .for'periodically varying the amount of current supplied to the ends of said electrodes,

and means for rotating' said hollow cylindrical electrode.

12. In an electric furnace, the combination of a furnace chamber having a ollow cylindrical electrode, an electrode within and concentric to Silld first-mentioned electrode, a source of electricity, connections to both ends of each of said electrodes, means for periodically varying the amount of current supplied to the ends of said electrodes, and means for rotating said hollow cylindrical electrode, the'axis of said electrodes being inclined to the horizontal.

13. In an electric furnace, the combination of a furnace chamber having a hollow cylindrical electrode, an electrode within and concentric to saidfirst-mentioned elec-' trode, a source of electricity, connections to both ends of each of said electrodes, means for periodically carying the amount of current supplied means for rotating'said hollow cylindrical electrode, the axis of said electrodes being inclined to the horizontal,,and a solenoid substantially concentric with and surrounding said electrodes.

14. In an electric furnace, the combina-- tion of concentric electrodes, forming be tween them a long air-gap of substantially uniform width, a source of electricity, co

nections between said source and said elec trodes, whereby an arc may be formed between said electrodes, and means to cause said are to reciprocate along said electrodes. 15. In an electric furnace, the combination of concentric electrodes, forming between them a long air-gap of substantially uniform width, a source of electricity, connections between said'source and said electrodes, whereby an arc may be formed between said electrodes, means to cause said,

arc to reciprocate along said electrodes, and means for causing said arc to rotate about the axis of said electrodes.

16. An electric heating device comprising lon itudinally extending adjacent arcin sur aces, and means for so supplying to sai surfaces varying electrical energy as to cause the movement of the are established therebetween. 17. An electric furnace comprising 1ongitudinally extending adjacent arcing surto the ends of said electrodes,

faces, an electric circuit including said electrodes and a source of electrical energy, and means for varying the energy supplied to opposite ends of said electrodes reciprocally.

18. An electric furnace comprising longitudinally extending adjacent arcing surfaces, an electric circuit including said electrodes and a source of electrical energy, and means for simultaneously varying the energy supplied to opposite ends of said electrodes reciprocally and periodically.

19. In an electric furnace, the combination of a hollow electrode, an electrode within the first mentioned electrode, means for supplying electrical energy to said electrodes to form an arc therebetween, means for causing the rotation of the are about the inner electrode, and means for so varying the energysupplied to said electrodes as to cause the longitudinal travel of the arc.

20. The process of electric furnace Working which'consists in causing an arc to reciprocate to-and-fro Within a heating chamber, and passing the material to be treated through said heating chamber during the reciprocation of said arc.

21. The process of electric furnace working which consists in subjecting the material to be treated to the action of a radial arc discharge in a hollow cylindrical. heating chamber, and causing the arc discharge to reciprocate to-and-fro within said chamber.

22. The process of electric furnace work ing which consists in subjecting the material to be treated to the ,action of a radial arc discharge in a rotating hollow cylindrical heating chamber, and causing the arc discharge to reciprocatelongitudinally in said chamber.

23. The process of electric furnace working, which consists in subjecting the material to be treated to the action of an arc dis charge through the material and between substantially parallel electrodes, and causing the arc discharge to reciprocate to and fro between said electrodes in a direction transverse to the normal travel of the are.

24. The process of electric furnace working, which consists in subjecting the material to be treated to the action of an arc discharge between substantially parallel electrodes, and causing the arc discharge to reciprocate to and fro between said electrodes by supplyingLvarying amounts of electricity to both ends of said electrodes.

The process of electric furnace workassesseing, which consists in forming an are be tween substantially parallel electrodes, sup- 26. The process of electric furnace worlc.

ing, which consists in passing the material to be treated through a rotatable hollow electrode, and forming in said electrode a diffused electric discharge.

27. The process of electric furnace working, which consists in passing the material to be treated through a rotatable hollow electrode, forming in said electrode a diffused electric discharge, and causing said discharge to reciprocate to and fro longitudinally of said chamber.

28. In an electricfurnace, the combination of two electrodes, one of said electrodes being a rotatable hollow electrode.

29. In an electric furnace, the combination of two electrodes, one of said electrodes being a rotatable hollow electrode and the other electrode being located within said hollow electrode.

30. In an electric furnace, the combination of a rotatable electrode and a second electrode, and means for forming an arc there between.

31. In an electric furnace, an inclosed heating chamber having a rotating electrode surface therein.

32. In an electric furnace, the combination of a rotatable hollow elect-rode forming an inclosed heating chamber, a second electrode therein, means for forming an arc therein, and means for rotating said are.

33. In an electric furnace, the combination of a rotatable hollow electrode forming an inclosed heating chamber, a second electrode therein, means for forming an arc therein, and means for diffusing said arc.

34. I11 an electric furnace, the combination of an inclosed heating chamber, means for forming a diffused electric discharge therein, and means for, causing solid materials to pass in contact with said discharge.

In testimony whereof, I have signed my name in presence of two-witnesses, this twenty-seventh day of October, 1896.

ERWIN F. VON wI ows'KY.

lVitnesses:

OTTO E. Snrrnns, ARTHUR SMITH. 

